Collaborations and License Agreements - Additional Information (Detail)	1 Months Ended																			3 Months Ended					12 Months Ended		27 Months Ended	36 Months Ended	39 Months Ended
	Feb. 28, 2019 USD ($)	Jan. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Nov. 30, 2018 USD ($)	Oct. 31, 2018 USD ($)	Aug. 31, 2018 USD ($)	Apr. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Feb. 28, 2018 USD ($)	Oct. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Apr. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2012 USD ($)	Mar. 31, 2010 USD ($)	Dec. 31, 2006 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($) Installment Indication	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2015 USD ($)	Feb. 28, 2018 USD ($)	Nov. 30, 2018 USD ($)	Feb. 28, 2019 USD ($)	Feb. 28, 2017 USD ($)	Oct. 14, 2016	Apr. 30, 2014 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement date month and year																					2018-12
Revenues																					$ 1,611,000			$ 1,026,000
Deferred revenue, current portion			$ 1,658,000																		1,974,000	$ 1,658,000
Amounts due from pursuant to the cost-sharing provisions			3,026,000																		2,571,000	3,026,000
Collaboration and Licensing Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenues																					1,454,000			980,000
Partnership Royalties
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenues																					$ 157,000			46,000
Development and Regulatory Milestone Events
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment due		$ 2,300,000
CANbridge
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement date																					Mar. 31, 2016
Allocation of upfront payment						$ 700,000
CANbridge | Licensing Agreements
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment received													$ 1,000,000
Upfront payment, withholding taxes													$ 100,000
Number of installments paid | Installment																					2
Revenue recognized from reimbursement of manufacturing development activities											$ 500,000	$ 500,000									$ 1,000,000				$ 1,000,000
Collaborations and license agreements, time period from first commercial sale of certain product upon which the agreement expires																					10 years
Description of royalty percentage receivable on net sales																					Upon commercialization, the Company is eligible to receive a tiered royalty, with a percentage range in the low double-digits, on net sales of approved licensed products.
Upfront consideration received upon execution														$ 1,000,000
Transaction price																							$ 4,000,000
Performance obligation																							0
CANbridge | Licensing Agreements | Collaboration and Licensing Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenues																							2,000,000
CANbridge | Licensing Agreements | Commercial Milestone Payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborations and license agreements, expected milestone receivable																					$ 90,000,000
CANbridge | Licensing Agreements | Additional Development and Regulatory Milestone Events
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborations and license agreements, expected milestone receivable																					$ 40,000,000
CANbridge | Licensing Agreements | Development and Regulatory Milestone Events
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and licensing revenue						2,000,000
Collaborations and license agreements, expected milestone receivable						2,000,000
CANbridge | Licensing Agreements | Development and Regulatory Milestone Events
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and licensing revenue						2,000,000
EUSA
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Description of royalty percentage receivable on net sales																					The Company is also eligible to receive tiered double-digit royalties on net sales, if any, of licensed products in the EUSA Licensed Territories ranging from a low double digit up to mid-twenty percent depending on the level of annual net sales.
Transaction price																					$ 12,500,000	$ 10,500,000		8,500,000
Revenues																					1,611,000			1,026,000
Research and development reimbursement received											4,000,000										$ 6,500,000					$ 2,500,000
Percentage of EUSA cost-sharing for TIVO-3 trial																					50.00%
Collaborations and license agreements, expected milestone receivable	$ 2,000,000			$ 2,000,000					$ 2,000,000		4,000,000				$ 2,500,000
Payments received in connection with reimbursement milestones																					$ 2,000,000
Eligible number of indications | Indication																					3
Payments received in connection with additional indications																					$ 5,000,000
Potential payments received in connection with additional indications																					$ 335,000,000
Collaborations and license agreements, potential future payment as percentage of certain amounts the Company receives under sublicense agreements																					30.00%
Revenue, Information Used to Allocate Transaction Price																					The Company evaluated the promised goods and services at the inception of the EUSA Agreement under ASC 606. Based on this evaluation, the Company determined that $6.5 million in research and development payments by EUSA, including the $2.5 million upfront consideration received upon the execution of the EUSA Agreement in December 2015 and the $4.0 million payment upon the receipt of marketing approval from the EMA for tivozanib (FOTIVDA) for the treatment of RCC in August 2017, constituted the amount of the consideration that was included in the transaction price upon the adoption of ASC 606 on January 1, 2018 and attributed this amount to the Company’s single performance obligation
Revenue recognized as collaboration and licensing revenue related to the cumulative catch-up																											$ 700,000	$ 900,000	$ 1,000,000
Deferred revenue, current portion									$ 1,300,000												$ 1,000,000		$ 1,100,000				$ 1,300,000
Remaining performance obligation revenue expected to be recognized over month and year																					2022-04
Research and development payment recognized																					$ 1,600,000			1,000,000
Deferred revenue																					6,000,000
Deferred revenue continue to be recognized as collaboration and licensing revenue per quarter																					500,000
Reductions in research and development expenses																					1,700,000
EUSA | Milestone - UK Reimbursement Approval
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Allocation of upfront payment							$ 600,000
Collaborations and license agreements, expected milestone receivable								$ 2,000,000
EUSA | Milestone - German Reimbursement Approval
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Allocation of upfront payment		600,000
Collaborations and license agreements, expected milestone receivable			$ 2,000,000
EUSA | Milestone - Spain Reimbursement Approval | Scenario Forecast
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Allocation of upfront payment																				$ 600,000
Collaborations and license agreements, expected milestone receivable																				$ 2,000,000
EUSA | Partnership Royalties
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Sales royalties revenue recognized																					200,000			46,000
EUSA | Opt In To Planned Phase Three Study
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment to be received																					20,000,000
EUSA | Marketing Approval in France, Germany, Italy, Spain and the United Kingdom
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment to be received																					2,000,000
EUSA | Marketing Approval in Australia, Brazil, New Zealand, South Africa and Switzerland
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment to be received																					2,000,000
EUSA | Opt-in to Co-develop TiNivo Trial
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborations and license agreements, expected milestone receivable											$ 2,000,000
EUSA | TiNivo trial
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development reimbursement received										$ 2,000,000
Collaborations and license agreements, deferred research and development reimbursements																					300,000
EUSA | TiNivo trial | Research and development
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payments received and recorded as an increased (decreased) to expense pursuant to cost-sharing provisions																					100,000			300,000
Novartis
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborations and license agreements, expected milestone receivable																					0
Non refundable upfront payment																$ 15,000,000
Reimbursable inventory															$ 3,500,000
Novartis | Collaboration and Licensing Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and licensing revenue		2,300,000
Collaboration revenue																														$ 1,800,000
Biodesix
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amounts due from pursuant to the cost-sharing provisions																					300,000
Biodesix | FOCAL study
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contribution percentage of clinical, regulatory, manufacturing and other costs																																50.00%
Percentage of closeout project cost																															50.00%
Biodesix | FOCAL study | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Funding																																$ 15,000,000
Biodesix | FOCAL trial
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reductions in research and development expenses																					100,000			$ 100,000
Collaborations and license agreements, royalties payment on net sales																																10.00%
Collaborations and license agreements, royalties payment on revenue																																25.00%
Biogen Idec International GmbH
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Allocation of upfront payment					$ 700,000
Biogen Idec International GmbH | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Royalty payments																					$ 50,000,000
Biogen Idec International GmbH | Licensing Agreements | Development and Regulatory Milestone Events
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and licensing revenue						$ 2,000,000
St Vincent's Hospital Sydney Limited
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amendment agreement date																					2015-08
Future payment obligations																														$ 1,800,000
Time-based milestone obligation payment												$ 1,800,000
Additional time-based milestone obligation payable		$ 2,300,000
St Vincent's Hospital Sydney Limited | Development and Regulatory Milestone Events | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognition milestone method milestone payables																					$ 14,400,000
St Vincent's Hospital Sydney Limited | Licensing Agreements
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment received																					1,500,000
Kyowa Hakko Kirin | Opt In To Planned Phase Three Study | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development reimbursement potential opt-in payment																			$ 20,000,000
Kyowa Hakko Kirin | Licensing Agreements
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment received																					$ 5,000,000
Collaborations and license agreements, potential future payment as percentage of certain amounts the Company receives under sublicense agreements																					30.00%
Collaborations and license agreements, milestone payment																		$ 10,000,000
Collaborations and license agreements, potential future milestone payments, maximum amount																	$ 18,000,000
Term of royalty payment obligations																			12 years
Kyowa Hakko Kirin | Licensing Agreements | FDA Marketing Approval
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborations and license agreements, milestone payment																	$ 12,000,000